Coating-type underlayer coating forming composition for lithography containing naphthalene resin derivative

ABSTRACT

[Object] To provide a coating-type underlayer coating forming composition containing a naphthalene resin derivative.
 
[Means for Solving Problems] A coating-type underlayer coating forming composition for lithography comprising a compound of formula (1):
 
     
       
         
         
             
             
         
       
     
     wherein A is an organic group having an aromatic group, R 1  is hydroxy group, an alkyl group, an alkoxy group, a halogen group, a thiol group, an amino group or an amide group, m1 is the number of A substituted on the naphthalene ring and is an integer of 1 to 6, m2 is the number of R 1  substituted on the naphthalene ring and is an integer of 0 to 5, a sum of m1 and m2 (m1+m2) is an integer of 1 to 6, in cases where the sum is an integer other than 6, the reminder is hydrogen atom, and n is the number of repeating units ranging from 2 to 7000.

TECHNICAL FIELD

The present invention relates to a coating-type underlayer coatingforming composition for lithography that is effective on processing ofsemiconductor substrates, and a method for forming photoresist patternby use of the coating-type underlayer coating forming composition.

BACKGROUND ART

Conventionally, in the manufacture of semiconductor devices,micro-processing by lithography using a photoresist composition has beencarried out. The micro-processing is a processing method comprisingforming a thin film of a photoresist composition on a substrate to beprocessed, such as a silicon wafer or the like, irradiating actinic rayssuch as ultraviolet rays through a mask pattern on which a pattern for asemiconductor device is depicted, developing it to obtain a photoresistpattern, and etching the substrate to be processed by use of thephotoresist pattern as a protective film. However, in recent progress inhigh integration of semiconductor devices, there has been a tendencythat shorter wavelength actinic rays are being used, i.e., ArF excimerlaser beam (193 nm) has been taking the place of KrF excimer laser beam(248 nm). Along with this change, influences of random reflection andstanding wave of actinic rays from a substrate have become seriousproblems. Accordingly, it has been widely studied to provide ananti-reflective coating between the photoresist and the substrate to beprocessed (Bottom Anti-Reflective Coating, BARC).

As the anti-reflective coating, inorganic antireflective coatings madeof titanium, titanium dioxide, titanium nitride, chromium oxide, carbonor α-silicon, etc., and organic antireflective coatings made of a lightabsorbing substance and a high molecular compound are known. The formerrequires an installation such as a vacuum deposition apparatus, a CVD(chemical vapor deposition) apparatus or a sputtering apparatus, etc. Incontrast, the latter is considered advantageous in that it requires nospecial installation so that many studies have been made. For example,mention may be made of a novolak resin type anti-reflective coating andan acrylic resin type anti-reflective coating which have a hydroxylgroup being a crosslinking reaction group and a light absorbing group inthe same molecule (see, for example Patent Documents 1 and 2).

The physical properties desired for organic anti-reflective coatingmaterials include high absorbance to light and radioactive rays, nointermixing with a layer applied on the anti-reflective coating (beinginsoluble in a solvent used for materials applied on the anti-reflectivecoating), no diffusion of low molecular substances from theanti-reflective coating materials into the topcoat resist on applying ordrying with heat, and a higher dry etching rate than the photoresist(see, for example, Non-patent Documents 1, 2 and 3).

When miniaturization of resist pattern progresses in future, problemssuch as a low resolution and collapse of resist pattern afterdevelopment occur, and thus it is desired to make photoresists thinner.Therefore, it is difficult to obtain a film thickness of resist patternsufficient for the processing of substrates, and processes for providinga function as a mask in the substrate processing not only for resistpattern but also for coating-type underlayer coating formed between aresist and a semiconductor substrate to be processed become required. Asthe coating-type underlayer coating for such a process, a coating-typeunderlayer coating for lithography having a selection ratio of dryetching rate close to that of photoresists, a coating-type underlayercoating for lithography having a lower selection ratio of dry etchingrate than that of photoresists, or a coating-type underlayer coating forlithography having a lower selection ratio of dry etching rate than thatof semiconductor substrates, which is different from conventional highetch rate coating-type underlayers, becomes required (see, for exampleNon-patent Documents 4 and 5). It is also able to confer anti-reflectiveperformance to the coating-type underlayer coatings, and they can havethe function of the conventional anti-reflective coatings together.

On the other hand, for obtaining fine resist pattern, it begins to use aprocess in which the resist pattern and the coating-type underlayercoating are made thinner on dry etching of coating-type underlayercoating than the width of pattern on the development of photoresists. Asthe coating-type underlayer coating for such a process, a coating-typeunderlayer coating having a selection ratio of dry etching rate close tothat of photoresists which is different from conventional high etch rateanti-reflective coatings, becomes required. It is also able to conferanti-reflective performance to the coating-type underlayer coatings, andthey can have the function of the conventional anti-reflective coatingstogether.

Patent Document 1: U.S. Pat. No. 5,919,599Patent Document 2: U.S. Pat. No. 5,693,691

Non-patent Document 1: Tom Lynch et al., “Properties and Performance ofNear UV Reflectivity Control Layers”, US, in Advances in ResistTechnology and Processing XI, Omkaram Nalamasu ed., Proceedings of SPIE,1994, Vol. 2195, p. 225-229

Non-patent Document 2: G. Taylor et al., “Methacrylate Resist andAntireflective Coatings for 193 nm Lithography”, US, in Microlithography1999: in Advances in Resist Technology and Processing XVI, Will Conleyed., Proceedings of SPIE, 1999, Vol. 3678, p. 174-185

Non-patent Document 3: Jim D. Meador et al., “Recent Progress in 193 nmAntireflective Coatings, US, in Microlithography 1999: in Advances inResist Technology and Processing XVI, Will Conley ed., Proceedings ofSPIE, 1999, Vol. 3678, p. 800-809

Non-patent Document 4: Tadayoshi Kokubo, “Bilayer resist system: Forresolution of problems in process integration”, Japan, MNC 2002Technical Seminar, Forefront for Resist Process, 2002, p 29-42Non-patent Document 5: Yoshio Kawai, “High resolution positive typechemically-amplified bilayer resist”, Japan, MNC 2002 Technical Seminar,Forefront for Resist Process, 2002, p. 43-48

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

An object of the present invention is to provide a coating-typeunderlayer coating forming composition that is used for lithographyprocess in the production of semiconductor devices. Another object ofthe present invention is to provide a coating-type underlayer coatingfor lithography having a selection ratio of dry etching rate close tothat of photoresists, a coating-type underlayer coating for lithographyhaving a lower selection ratio of dry etching rate than that ofphotoresists, or a coating-type underlayer coating for lithographyhaving a lower selection ratio of dry etching rate than that ofsemiconductor substrates, that causes no intermixing with photoresistlayers and provides excellent photoresist pattern. In addition, thepresent invention can confer a property for absorbing effectivelyreflection light from substrates in a case where irradiation lighthaving a wavelength of 248 nm, 193 nm, 157 nm or the like is used in themicro-processing. Further, an object of the present invention is toprovide a method for forming a photoresist pattern, in which thecoating-type underlayer coating forming composition is used.

Means for Solving the Problem

Taking the above-mentioned present status into account, the presentinventors eagerly investigated, and as a result, they found the use of anaphthalene resin derivative having naphthalene derivative in the mainchain makes possible to form a coating-type underlayer coating forlithography having a selection ratio of dry etching rate close to thatof photoresists, a coating-type underlayer coating for lithographyhaving a lower selection ratio of dry etching rate than that ofphotoresists, or a coating-type underlayer coating for lithographyhaving a lower selection ratio of dry etching rate than that ofsemiconductor substrates, to confer an function as anti-reflectivecoating, and to control refractive Index n and attenuation coefficient kin 248 nm, 193 nm or 157 nm of the composition therefor, and theycompleted the present invention.

The present invention relates to the following aspects:

as a first aspect, a coating-type underlayer coating forming compositionfor lithography comprising a compound of formula (1):

wherein A is an organic group having an aromatic group, R₁ is hydroxygroup, an alkyl group, an alkoxy group, a halogen group, a thiol group,an amino group or an amide group, m1 is the number of A substituted onthe naphthalene ring and is an integer of 1 to 6, m2 is the number of R₁substituted on the naphthalene ring and is an integer of to 5, a sum ofm1 and m2 (m1+m2) is an integer of 1 to 6, in cases where the sum is aninteger other than 6, the reminder is hydrogen atom, and n is the numberof repeating units ranging from 2 to 7000;

as a second aspect, a coating-type underlayer coating formingcomposition for lithography comprising a compound of formula (2):

wherein A, R₁, m1, m2, and n are as defined in formula (1), Ar₁ is asubstituted or unsubstituted aromatic group;

as a third aspect, a coating-type underlayer coating forming compositionfor lithography comprising a compound of formula (3):

wherein X is a single bond, methylene group, C₂₋₁₀alkylene group, adivalent hydrocarbon group having C₂₋₁₀ether bond, or carbonyl group, Zis a linking group of —O— or —OC(═O)—, Ar₂ is an unsubstituted aromaticring or an aromatic ring substituted with carboxylic acid, a carboxylicacid ester group, hydroxy group, an alkyl group, an alkoxy group,sulfonic acid group, or a halogen group, and R₁, m1, m2 and n are asdefined in formula (1);

as a fourth aspect, a coating-type underlayer coating formingcomposition for lithography comprising a compound of formula (4):

wherein X and Z are as defined in formula (3), Ar₁ is as defined informula (2), Ar₂ is as defined in formula (3), and R₁, m1, m2, and n areas defined in formula (1);

as a fifth aspect, a coating-type underlayer coating forming compositionfor lithography comprising a compound of formula (5):

wherein X and Z are as defined in formula (3), Ar₂ is as defined informula (3), and R₁, m1, m2 and n are as defined in formula (1);

as a sixth aspect, the coating-type underlayer coating formingcomposition for lithography as described in any one of the first tofifth aspects, further comprising a crosslinking compound;

as a seventh aspect, the coating-type underlayer coating formingcomposition for lithography as described in any one of the first tofifth aspects, further comprising an acid, an acid generator, or both ofthem:

as an eighth aspect, the coating-type underlayer coating formingcomposition for lithography as described in the sixth aspect, furthercomprising an acid, an acid generator, or both of them;

as a ninth aspect, a coating-type underlayer coating for lithographyobtained by coating the coating-type underlayer coating formingcomposition as described in any one of the first to fifth aspects on asemiconductor substrate and baking it;

as a tenth aspect, a method for forming photoresist pattern for use inmanufacture of semiconductor device, comprising coating the coating-typeunderlayer coating forming composition as described in any one of thefirst to fifth aspects on a semiconductor substrate, and baking it toform a coating-type underlayer coating;

as an eleventh aspect, a method for manufacturing semiconductor devicecomprising the steps of:

forming a coating-type underlayer coating from the coating-typeunderlayer coatingforming composition as described in any one of the first to fifthaspects;forming a resist coating on the coating-type underlayer coating;forming a resist pattern by exposure to light and development;etching the coating-type underlayer coating by use of the resistpattern; and processing the semiconductor substrate by use of thepatterned coating-type underlayer coating; and

as a twelfth aspect, a method for manufacturing semiconductor devicecomprising the steps of

forming a coating-type underlayer coating from the coating-typeunderlayer coatingforming composition as described in any one of the first to fifthaspects;forming a hardmask on the coating-type underlayer coating;forming a resist coating further thereon;forming a resist pattern by exposure to light and development;etching the hardmask by use of the resist pattern;etching the coating-type underlayer coating by use of the patternedhardmask; andprocessing the semiconductor substrate by use of the patternedcoating-type underlayer coating.

EFFECT OF THE INVENTION

The present invention relates to a coating-type underlayer coatingformed by use of a resin having a naphthalene derivative in the mainchain, and a coating-g-type underlayer coating forming composition forforming the coating-type underlayer coating.

The coating-type underlayer coating forming composition of the presentinvention can form a good pattern shape of photoresists withoutintermixing of the coating-type underlayer coating with the part appliedthereon.

It is possible to confer a property for inhibiting effectivelyreflection from substrates on the coating-type underlayer coatingforming composition of the present invention, and thus the coating-typeunderlayer coating can combine an effect as antireflective coating.

The coating-type underlayer coating forming composition of the presentinvention can provide excellent coating-type underlayer coatings thathave a selection ratio of dry etching rate close to that ofphotoresists, a lower selection ratio of dry etching rate than that ofphotoresists, or a lower selection ratio of dry etching rate than thatof semiconductor substrates.

In order to prevent collapse of resist pattern after development withminiaturization of resist pattern, it is performed to make photoresiststhinner. The thin resists are required to be subjected to a process inwhich the resist pattern is transferred to the sublayer by etchingprocess, and the substrate processing is performed by use of thesublayer as a mask, and a process in which the step comprisingtransferring the resist pattern to the sublayer by etching process, andtransferring the pattern transferred to the sublayer to the layerapplied below the sublayer with a different gas composition is repeated,and finally the substrate processing is performed. The coating-typeunderlayer coating and the composition for forming the same according tothe present invention are effective for these processes. When thesubstrate processing is performed by use of the coating-type underlayercoating of the present invention, the coating-type underlayer coatinghas an etching resistance sufficiently for processing substrates (forexample thermal silicon oxide coating, silicon nitride coating,polysilicon coating or the like on a substrate).

On the other hand, for obtaining fine resist pattern, it begins to bealso used a process in which the resist pattern and the coating-typeunderlayer coating are made thinner on dry etching of coating-typeunderlayer coating than the width of pattern on the development ofphotoresists. The coating-type underlayer coating and the compositionfor forming the same according to the present invention are effectivefor this process, and has a selection property of dry etching rate closeto that of photo resists.

Further, the coating-type underlayer coating of the present inventioncan be used as a planarizing (flattening) coating, a resist underlayercoating, an anti-contamination coating of photoresist layer, or acoating having a dry etching selectivity. The coating-type underlayercoating makes possible to form photoresist pattern in lithographyprocess of the manufacture of semiconductor devices in an easy andprecise manner.

BEST MODE FOR CARRYING OUT THE INVENTION

The coating-type underlayer coating forming composition of the presentinvention comprises at least one of a naphthalene resin having thestructural unit of formula (1) and a naphthalene resin having thestructural unit of (2), and further a solvent. Further, the coating-typeunderlayer coating for lithography of the present invention comprises acrosslinking agent, a crosslinking catalyst, and a surfactant, etc. asarbitrary components. The coating-type underlayer coating forlithography of the present invention contains a solid content being allcomponents except the solvent in an amount of 0.1 to 70% by weight,preferably 0.5 to 50% by weight, further preferably 1 to 40% by weight.In the solid content, the naphthalene derivative of formula (1) or thenaphthalene derivative of formula (2) is contained in an amount of 5 to100% by weight, preferably 7 to 95% by weight, further preferably 10 to90% by weight. The naphthalene resin having the structural unitrepresented by formula (1) or (2) in the present invention can be usedas a light absorbing compound on patterning of photoresists. Thenaphthalene compound in the present invention has a high absorption forlight at photosensitive characteristic wavelength region ofphotosensitive components in a photoresist layer provided on ananti-reflective coating, and prevent standing wave caused by reflectionfrom a substrate or random reflection due to unevenness on the substratesurface.

The naphthalene resin having the structural unit represented by formula(1) or (2) is an oligomer or a polymer in which the repeating unit n is2 to 7000, or 2 to 5000, or 2 to 300. The molecular weight thereofvaries depending on the application solvent used, solution viscosity,film shape or the like, but ranges from 400 to 1000000, preferably 500to 500000, further preferably 500 to 300000 in weight average molecularweight.

The naphthalene resin having the structural unit represented by formula(1) or (2) has substituent (A). That is, the resin is a naphthalenenovolak resin having side chain (A) having an aromatic ring or ahetero-aromatic ring at the end. In addition, the structural unit offormula (1) can have substituent (R₁) consisting of hydroxy group,C₁₋₄alkyl group, C₁₋₄alkoxy group and a halogen group such as bromineatom, the number m1 of substituent A on the naphthalene ring is 1 to 6,and the number m2 of substituent (R₁) is 0 to 5, the total number ofsubstituent A and substituent (R₁) per naphthalene ring is 1 to 6(m1+m2=1 to 6), and in cases where the total number is an integer otherthan 6, the reminder is hydrogen atom.

The compound of formula (3) is a specific polymer among those of formula(1). In formula (3), X in substituent (A) is a single bond, methylenegroup, C₂₋₁₀alkylene group, a divalent hydrocarbon group havingC₂₋₁₀ether bond, or carbonyl group, Z is a linking group of —O— or—OC(═O—, Ar₂ is an unsubstituted aromatic ring or an aromatic ringsubstituted with carboxylic acid, a carboxylic acid ester group, hydroxygroup, an alkyl group, an alkoxy group, sulfonic acid group, a halogengroup, thiol group, amino group, or amide group. The aromatic ring (Ar₂)includes benzene ring, naphthalene ring, anthracene ring, orheterocyclic ring thereof containing hetero atom such as nitrogen atomor the like.

The unit of formula (1) includes further the resin of formula (2) havinga novolak structure of a naphthalene derivative with other aromaticcompound. In formula (2), the other aromatic compound (Ar₁) constitutinga novolak structure with a naphthalene derivative includes for examplebenzene, naphthalene, anthracene, or derivative thereof containinghetero atom such as nitrogen atom or the like, or derivative thereofobtained by substituting the above-mentioned compound with carboxylicacid, a carboxylic acid ester group, hydroxy group, an alkyl group, analkoxy group, sulfonic acid group, a halogen group, thiol group, aminogroup, or amide group. Among them, the compound corresponding to formula(5) in which (Ar₁) is benzene is preferable. The compound of formulae(1) and (2) can be produced by subjecting naphthalene hydroxide andacetaldehyde to condensation polymerization to produce a naphthaleneresin, reacting the naphthalene resin with epichlorohydrin to produce anaphthalene resin having glycidyl ether group, and reacting theresulting naphthalene resin with carboxylic acid or hydroxide ofbenzene, naphthalene or anthracene. Both ends of the compounds offormulae (1) and (2), the compounds of formulae (3) to (5) beingspecific compounds thereof, and exemplified compounds thereof can havehydrogen atom or hydroxy group.

For the above-mentioned production methods, known conditions forproduction can be applied. For example, the reaction condition forobtaining novolak comprises a reaction at a temperature of 50 to 180° C.for 4 to 72 hours by use of a catalyst such as oxalic acid or the likein the presence or absence of a solvent such as N-methylpyrrolidone orthe like. The reaction condition for obtaining glycidyl ether comprisesa reaction at a temperature of 50 to 180° C. for 4 to 72 hours by use ofa catalyst such as benzyl triethyl ammonium chloride or the like in asolvent such as propylene glycol monomethyl ether or the like, andfurther a reaction at a temperature of 50 to 180° C. for 4 to 72 hoursby use of a catalyst such as sodium hydroxide or the like in thepresence or absence of a solvent such as propylene glycol monomethylether or the like. The condition for the reaction of glycidyl ethergroup with an aromatic carboxylic acid or hydroxide comprises a reactionat a temperature of 50 to 180° C. for 4 to 72 hours by use of a catalystsuch as benzyl triethyl ammonium chloride or the like in a solvent suchas propylene glycol monomethyl ether or the like. The present inventionis not limited to these production methods, and the intended compoundcan be produced by combining a known production method for polymershaving a novolak resin in the main chain and an aromatic substituent inthe side chain.

Specific examples of the structural unit of the naphthalene resin offormulae (1) to (5) can be shown by the following general formulae.

In formulae (6) to (157), number n1 is the number of substituents on thearomatic ring, and is at least 1 and at most the number of hydrogenatoms present on the aromatic ring. In addition, when some n1(s)originated from different substituents on the same aromatic ring arepresent, each n1 is at least 1 and the sum thereof is at most the numberof hydrogen atoms present on the aromatic ring. Further, n is the numberof repeating units, and has the same meaning as that of theabove-mentioned formulae (1) to (5).

It is preferable to crosslink the coating-type underlayer coatingforming composition for lithography of the present invention by heatingafter application in order to prevent any intermixing with photoresistscoated thereon, and the coating-type underlayer coating formingcomposition for lithography of the present invention can contain furthera crosslinking agent component. The crosslinking agent includesmelamines, substituted ureas, or polymers thereof and the like. Thecrosslinking agent has preferably at least two crosslink-formingsubstituents, and are compounds such as methoxymethylated glycoluril,butoxymethylated glycoluril, methoxymethylated melamine,butoxymethylated melamine, methoxymethyl benzoguanamine,butoxymethylbenzoguanamine, methoxymethyl urea, butoxymethyl urea,methoxymethyl thiourea, or methoxymethyl thiourea or the like. Inaddition, the condensation products of these compounds can be used. Theaddition amount of the crosslinking agent may vary depending on thecoating solvents used, the underlying substrate used, the viscosity ofthe solvent required, the shape of the coating required, etc., andusually 0.001 to 80% by weight, preferably 0.01 to 50% by weight,further preferably 0.05 to 40% by weight based on the whole solidcontent. These crosslinking agent may cause a crosslinking reaction dueto self-condensation. In a case where any crosslinking substituent ispresent on the above-mentioned polymer compound, the crosslinking agentcan cause a crosslinking reaction with these crosslinking substituents.

In the present invention, as a catalyst for accelerating theabove-mentioned crosslinking reaction, an acidic compound such asp-toluene sulfonic acid, trifluoro methane sulfonic acid, pyridiniump-toluene sulfonic acid, salicylic acid, sulfosalicylic acid, citricacid, benzoic acid, hydroxybenzoic acid, naphthalene carboxylic acid orthe like, or/and a thermal acid generator such as2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyltosylate, other organic sulfonic acid alkyl esters or the like can beadded. The addition amount thereof is 0.0001 to 20% by weight,preferably 0.0005 to 10% by weight based on the whole solid content.

In the coating-type underlayer coating forming composition forlithography of the present invention, a photoacid generator can be addedin order to conform the acidity of an underlayer coating to that of aphotoresist provided on the underlayer coating in lithography process.Preferable photoacid generators are for example onium salt typephotoacid generators such as bis(4-t-butylphenyl)iodoniumtrifluoromethane sulfonate, triphenylsulfonium trifluoromethanesulfonate or the like, halogen-containing compound type photoacidgenerators such as phenyl-bis(trichloromethyl) s-triazine or the like,sulfonic acid type photoacid generators such as benzoin tosylate,N-hydroxysuccinimide trifluoro methane sulfonate or the like. Thephotoacid generator can be added in an amount of 0.2 to 10% by weight,preferably 0.4 to 5% by weight based on the whole solid content.

In the materials for the coating-type underlayer coating of the presentinvention, further light absorbing agents, rheology controlling agents,adhesion auxiliaries, surfactants or the like can be added, ifnecessary, in addition to the above-mentioned components.

The further light absorbing agents include for example commerciallyavailable light absorbing agents described in “Technique and Market ofIndustrial Pigments” (CMC Publishing Co., Ltd.) or “Dye Handbook”(edited by The Society of Synthetic Organic Chemistry, Japan), forexample C.I. Disperse Yellow 1, 3, 4, 5, 7, 8, 13, 23, 31, 49, 50, 51,54, 60, 64, 66, 68, 79, 82, 88, 90, 93, 102, 114 and 124; C.I. DisperseOrange 1, 5, 13, 25, 29, 30, 31, 44, 57, 72 and 73; C.I. Disperse Red 1,5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72, 73, 88, 117, 137, 143, 199 and210; C.I. disperse Violet 43; C.I. Disperse Blue 96; C.I. FluorescentBrightening Agent 112, 135 and 163; C.I. Solvent Orange 2 and 45; C.I.Solvent Red 1, 3, 8, 23, 24, 25, 27 and 49; C.I. Pigment Green 10; C.I.Pigment Brown 2, and the like can be suitably used. The light absorbingagent is generally added in an amount of 10% by weight or less,preferably 5% by weight or less based on the whole solid content of thematerials for the coating-type underlayer coating material forlithography.

The rheology controlling agents are mainly added in order to increasethe flowability of the coating-type underlayer coating formingcomposition, particularly to increase evenness in film thickness of thecoating-type underlayer coating and filling property of the coating-typeunderlayer coating forming composition in holes. Specific examples arephthalic acid derivatives such as dimethyl phthalate, diethyl phthalate,diisobutyl phthalate, dihexyl phthalate, butyl isodecyl phthalate or thelike, adipic acid derivatives such as di-n-butyl adipate, drisobutyladipate, diisooctyl adipate, octyldecyl adipate or the like, maleic acidderivatives such as di-n-butyl maleate, diethyl maleate, dinonyl maleateor the like, oleic acid derivatives such as methyl oleate, butyl oleate,tetrahydrofurfuryl oleate or the like, stearic acid derivatives such asn-butyl stearate, glyceryl stearate, or the like. The rheologycontrolling agents are added in a proportion of usually less than 30% byweight based on the whole solid content of the materials for thecoating-type underlayer coating.

The adhesion auxiliaries are mainly added in order to increase adhesiveproperty between a substrate or a photoresist and a coating-typeunderlayer coating forming composition, particularly in order not tocause peeling of photoresists in development. Specific examples arechlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane,methyl diphenylchlorosilane, chloromethyldimethyl chlorosilane or thelike, alkoxysilanes such as trimethylmethoxysilane,dimethyldiethoxysilane, methyldimethoxysilane,dimethylvinylethoxysilane, diphenyldimethoxysilane,phenyltriethoxysilane or the like, silazanes such ashexamethyldisilazane, N,N′-bis(trimethylsilyl)urea,dimethyltrimethylsilylamine, trimethylsilylimidazole or the like,silanes such as vinyltrichlorosilane, γ-chloropropyltrimethoxysilane,γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane or thelike, heterocyclic compounds such as benzotriazole, benzimidazole,indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole,2-mercaptobenzoxazole, urazole, thiouracyl, mercaptolmidazole,mercaptopyrimidine or the like, ureas such as 1,1-dimethylurea,1,3-dimethylurea or the like, or thiourea compounds, etc. The adhesionauxiliaries are added in a proportion of usually less than 5% by weight,preferably 2% by weight based on the whole solid content of thematerials for the coating-type underlayer coating material forlithography.

In the coating-type underlayer coating material for lithographyaccording to the present invention, surfactants can be added in ordernot to cause pinholes or striation and in order to further improvecoating property to surfaces with unevenness. As the surfactants,mention may be made of, for example, nonionic surfactants such aspolyoxyethylene alkyl ethers, e.g., polyoxyethylene lauryl ether,polyoxyethylene stearyl ether, polyoxyethylene cetyl ether,polyoxyethylene oleyl ether, etc., polyoxyethylene alkyl allyl ethers,e.g., polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenolether, etc.; polyoxyethylene/polyoxypropylene block copolymers, sorbitanfatty acid esters, e.g., sorbitan monolaurate, sorbitan monopalmitate,sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitantristearate, etc., polyoxyethylene sorbitan fatty acid esters, e.g.,polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitanmonopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylenesorbitan trioleate, polyoxyethylene sorbitan tristearate, etc.; fluorinebased surfactants, e.g., trade name: EFROP EF301, EF303, EF352(manufactured by Tochem Products Co., Ltd.), trade name: MEGAFAC F171,F173 (manufactured by Dainippon Ink and Chemicals, Inc.), trade name:FLUORAD FC430, FC431 (manufactured by Sumitomo 3M Limited), trade name:ASAHI GUARD AG710, SURFLON S-382, SC101, SC102, SC103, SC104, SC105,SC106 (manufactured by Asahi Glass Co., Ltd.); organosiloxane polymerKP341 (manufactured by Shinetsu Chemical Co., Ltd.), etc. The blendingamount of the surfactants is usually 0.2% by weight or less, preferably0.1% by weight or less based on the whole solid content of the materialsfor the coating-type underlayer coating material of the presentinvention. The surfactants may be added singly or in combination of twoor more.

Solvents that can be used for dissolving the above-mentioned polymercompounds and the crosslinking agent components, crosslinking catalystand the like in the present invention, include ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, methyl cellosolveacetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether,diethylene glycol monoethyl ether, propylene glycol, propylene glycolmonomethyl ether, propylene glycol monomethyl ether acetate, propyleneglycol propyl ether acetate, toluene, xylene, methyl ethyl ketone,cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate,methyl 2-hydroxy-3-methylbutanoate, methyl 3 methoxypropionate, ethyl3-methoxypropionate, ethyl 3-ethoxypropionate, methyl3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate butylacetate, ethyl lactate, butyl lactate or the like. These organicsolvents may be used singly or in combination of two or more of them.

Further, high boiling solvents such as propylene glycol monobutyl etheror propylene glycol monobutyl ether acetate, etc. may be mixed and used.Among these solvents, from viewpoint of improvement of levelingproperty, the following solvents are preferable: propylene glycolmonomethyl ether, propylene glycol monomethyl ether acetate, ethyllactate, butyl lactate, and cyclohexanone, etc.

The photoresist to be coated on the coating-type underlayer coating forlithography may be a negative type or a positive type, and includes apositive type photoresist consisting of a novolak resin and1,2-naphthoquinone diazide sulfonic acid ester, a chemically-amplifiedtype photoresist which consists of a photoacid generator and a binderhaving a group which is decomposed with an acid and increases alkalidissolution rate, a chemically-amplified type photoresist consisting ofan alkali-soluble binder, a photoacid generator, and a low molecularcompound which is decomposed with an acid and increases the alkalidissolution rate of the photoresist, a chemically-amplified photoresistconsisting of a photoacid generator, a binder having a group which isdecomposed with an acid and increases the alkali dissolution rate, and alow molecular compound which is decomposed with an acid and increasesthe alkali dissolution rate of the photoresist, and a photoresist havingSi atom in the skeleton, and for example, trade name: APEX-Emanufactured by Rhom and Haas Company.

The developer that can be used for the photoresist having coating-typeunderlayer coating formed by using the coating-type underlayer coatingmaterial for lithography of the present invention includes aqueoussolutions of alkalis, for example inorganic alkalis such as sodiumhydroxide, potassium hydroxide, sodium carbonate, sodium silicate,sodium metasilicate, ammonia water or the like, primary amines such asethyl amine, n-propyl amine or the like, secondary amines such asdiethyl amine, di-n-butyl amine or the like, tertiary amines such astriethyl amine, methyldiethyl amine or the like, alcohol amines such asdimethyl ethanol amine, triethanol amine or the like, quaternaryammonium salts such as tetramethylammonium hydroxide, tetraethylammoniumhydroxide, choline or the like, cyclic amine such as pyrrole, piperidineor the like, and so on. Further, alcohols such as isopropyl alcohol orthe like, nonionic surfactants or the like can be added and used inthese aqueous solution of alkalis. Among them, preferable developers arequaternary ammonium salts, and tetramethyl ammonium hydroxide andcholine are more preferable.

Next, the method for forming photoresist pattern according to thepresent invention is described. On a substrate (for example, transparentsubstrate such as silicon/silicon dioxide coat substrate, glasssubstrate, ITO substrate or the like) that is used for the manufactureof precision integrated circuit elements, the coating-type underlayercoating forming composition is coated by a suitable coating method, forexample, with a spinner, a coater or the like, and thereafter thesubstrate is baked to fabricate a coating-type underlayer coating. Thefilm thickness of the coating-type underlayer coating is preferably 0.01to 3.0 μm. The baking after coating is performed under a condition of atemperature of 80 to 250° C. and a time of 1 to 120 minutes Goodphotoresist pattern can be obtained by applying a photoresist directlyon the coating-type underlayer coating or on one to some layers ofcoatings formed on the coating-type underlayer coating if necessary,exposing to light through a predetermined mask, developing, rinsing anddrying. If necessary, post exposure bake (PEB) can be also performed.Then, the part of the coating-type underlayer coating that correspondsto the part of the photoresist removed by the above-mentioneddevelopment step can be removed by dry etching to form a desired patternon the substrate.

That is, semiconductor devices can be produced through the followingsteps: a step of forming a coating-type underlayer coating from thecoating-type underlayer coating forming composition on a semiconductorsubstrate, a step of forming a resist coating thereon, a step of forminga resist pattern by exposure to light and development, a step of etchingthe coating-type underlayer coating by the resist pattern, and a step ofprocessing the semiconductor substrate by the patterned coating-typeunderlayer coating.

When miniaturization of resist pattern progresses in future, problemssuch as a low resolution and collapse of resist pattern afterdevelopment occur, and thus it is desired to make photoresists thinner.Therefore, it is difficult to obtain a film thickness of resist patternsufficient for the processing of substrates, and processes for providinga function as a mask in the substrate processing not only for resistpattern but also for coating-type underlayer coating formed between aresist and a semiconductor substrate to be processed become required. Asthe coating-type underlayer coating for such a process, a coating-typeunderlayer coating for lithography having a selection ratio of dryetching rate close to that of photoresists, a coating-type underlayercoating for lithography having a lower selection ratio of dry etchingrate than that of photoresists, or a coating-type underlayer coating forlithography having a lower selection ratio of dry etching rate than thatof semiconductor substrates, which is different from conventional highetch rate coating-type underlayer coatings, becomes required. It is alsoable to confer anti-reflective performance to the coating-typeunderlayer coatings, and they can have the function of the conventionalanti-reflective coatings together.

On the other hand, for obtaining fine resist pattern, it begins to use aprocess in which the resist pattern and the coating-type underlayercoating are made thinner on dry etching of coating-type underlayer thanthe width of pattern on the development of photoresists. As thecoating-type underlayer coating for such a process, a coating-typeunderlayer coating for lithography having a selection ratio of dryetching rate close to that of photoresists which is different fromconventional high etch rate coating-type underlayer coatings, becomesrequired. It is also able to confer anti-reflective performance to thecoating-type underlayer coatings, and they can have the function of theconventional anti-reflective coatings together.

In the present invention, a photoresist can be coated directly on acoating-type underlayer coating formed by the coating-type underlayercoating forming composition of the present invention, or on one to somelayers of coatings formed on the coating-type underlayer coating ifnecessary. Therefore, even when a thin photoresist is coated in order toprevent collapse of pattern due to narrow width of photoresist pattern,it make possible to perform the processing of substrates by selecting asuitable etching gas.

That is, semiconductor devices can be produced through the followingsteps; a step of forming a coating-type underlayer coating from thecoating-type underlayer coating forming composition on a semiconductorsubstrate, a step of forming a hardmask from a coating materialcontaining silicon component or the like thereon, a step of forming aresist coating further thereon, a step of forming a resist pattern byexposure to light and development, a step of etching the hardmask by theresist pattern, a step of etching the coating-type underlayer coating bythe patterned hardmask, and a step of processing the semiconductorsubstrate by the patterned coating-type underlayer coating.

The coating-type underlayer coating for lithography containing anaphthalene resin according to the present invention has characteristicsthat can provide dry etching rate suitable for satisfying theserequirements.

Taking into account the effect of the coating-type underlayer coatingforming composition for lithography of the present invention as ananti-reflective coating, it does not diffuse into photoresists on dryingwith heat as the light absorbing moiety is incorporated in the skeleton,and an antireflection effect is high as the light absorbing moiety has ahigh light absorption property.

The coating-type underlayer coating forming composition for lithographyof the present invention has a thermal stability, and can preventcontamination on the upper layer coating due to decomposed products onbaking and provide a wide temperature margin in baking step.

Further, depending on the processing condition, the coating-typeunderlayer coating material for lithography of the present invention canbe used as a coating having a function of preventing light reflectionand a function of preventing an interaction between a substrate and aphotoresist, or an adverse effect to the substrate by the material usedfor the photoresist or substances generated on exposure to thephotoresist.

Hereinafter, the present invention will be further described based onexamples and comparative examples but the present invention is notlimited thereto.

EXAMPLES Synthetic Example 1

After 50.0 g of the compound of formula (158) (manufactured by DaicelChemical Industries, Ltd., trade name: EHPE3150) and 57.4 g of9-anthracene carboxylic acid were dissolved in 435.7 g of propyleneglycol monomethyl ether, 1.5 g of benzyl triethyl ammonium was added,and the resulting mixture was refluxed for 24 hours to obtain a solutionof the polymer compound of formula (159). GPC analysis of the resultingpolymer compound showed that it had a weight average molecular weight of3000 in terms of standard polystyrene.

Synthetic Example 2

After 50.0 g of the compound of formula (160) (manufactured by NipponSteel Chemical Co., Ltd., trade name: ESN175S) and 37.3 g of9-anthracene carboxylic acid were dissolved in 353.0 g of propyleneglycol monomethyl ether, 1.0 g of benzyl triethyl ammonium was added,and the resulting mixture was refluxed for 24 hours to obtain a solutionof the polymer compound of formula (161). GPC analysis of the resultingpolymer compound showed that it had a weight average molecular weight of2500 in terms of standard polystyrene.

Synthetic Example 3

After 50.0 g of the compound of formula (162) (manufactured by NipponSteel Chemical Co., Ltd., trade name: ESN375) and 60.1 g of 9-anthracenecarboxylic acid were dissolved in 447.0 g of propylene glycol monomethylether, 1.6 g of benzyl triethyl ammonium was added, and the resultingmixture was refluxed for 24 hours to obtain a solution of the polymercompound of formula (163). GPC analysis of the resulting polymercompound showed that it had a weight average molecular weight of 2500 interms of standard polystyrene.

Synthetic Example 4

After 21 g of glycidyl methacrylate and 39 g of 2-hydroxypropylmethacrylate were dissolved in 242 g of propylene glycol monomethylether, the temperature was raised to 70° C. Then, while maintaining thereaction solution at 70° C., 0-6 g of azobisisobutyronitrile was addedand the solution was subjected to a reaction at 70° C. for 24 hours toobtain a solution of the polymer compound of formula (164). GPC analysisof the resulting polymer compound showed that it had a weight averagemolecular weight of 50000 in terms of standard polystyrene.

In 100 g of a solution containing 20 g of the above-mentioned resin, 10g of 9 anthracene carboxylic acid and 0.3 g of benzyltriethyl ammoniumchloride were added, and reacted at 130° C. for 24 hours to obtain asolution of the polymer compound of formula (165).

Synthetic Example 5

After 13.2 g of hydroxypropyl methacrylate and 6.8 g of benzylmethacrylate were dissolved in 74.4 g of tetrahydrofuran, thetemperature was raised to 70° C. Then, while maintaining the reactionsolution at 70° C. 0.2 g of azobisisobutyronitrile was added and thesolution was subjected to a reaction at 70° C. for 24 hours. After thereaction solution was cooled, it was put in diethyl ether to make thepolymer re-precipitated. The resulting polymer was dried with heat toobtain the resin of formula (166) GPC analysis of the resulting polymercompound showed that it had a weight average molecular weight of 70000in terms of standard polystyrene.

Example 1

In 10 g of a solution containing 2 g of the polymer compound obtained inSynthesis Example 2 in propylene glycol monomethyl ether, 0.4 g oftetrabutoxymethyl glycol uril and 0.05 g of pyridinium p-toluenesulfonic acid were mixed, and dissolved in 3.0 g of propylene glycolmonomethyl ether and 11.0 g of ethyl lactate to obtain a solution.Thereafter, the solution was filtered through a micro filter made ofpolyethylene having a pore diameter of 0.10 μm and then through a microfilter made of polyethylene having a pore diameter of 0.05 μm to preparea solution for coating-type underlayer coating for lithography.

Example 2

In 10 g of a solution containing 2 g of the polymer compound obtained inSynthesis Example 3 in propylene glycol monomethyl ether, 0.4 g oftetrabutoxymethyl glycol uril and 0.05 g of pyridinium p-toluenesulfonic acid were mixed, and dissolved in 3.0 g of propylene glycolmonomethyl ether and 11.0 g of ethyl lactate to obtain a solution.Thereafter, the solution was filtered through a micro filter made ofpolyethylene having a pore diameter of 0.10 μm and then through a microfilter made of polyethylene having a pore diameter of 0.05 μm to preparea solution for coating-type underlayer coating for lithography.

Example 3

In 5 g of a solution containing 1 g of the polymer compound obtained inSynthesis Example 1 in propylene glycol monomethyl ether and 5 g of asolution containing 1 g of the polymer compound obtained in SynthesisExample 2, 0.4 g of tetrabutoxymethyl glycol uril and 0.05 g ofpyridinium p-toluene sulfonic acid were mixed, and dissolved in 3.0 g ofpropylene glycol monomethyl ether and 11.0 g of ethyl lactate to obtaina solution. Thereafter, the solution was filtered through a micro filtermade of polyethylene having a pore diameter of 0.10 μm and then througha micro filter made of polyethylene having a pore diameter of 0.05 μm toprepare a solution for coating-type underlayer coating for lithography.

Example 4

In 8 g of a solution containing 1.6 g of the polymer compound obtainedin Synthesis Example 1 in propylene glycol monomethyl ether and 2 g of asolution containing 0.4 g of the polymer compound obtained in SynthesisExample 2, 0.4 g of tetrabutoxymethyl glycol uril and 0.05 g ofpyridinium p-toluene sulfonic acid were mixed, and dissolved in 3.0 g ofpropylene glycol monomethyl ether and 11.0 g of ethyl lactate to obtaina solution. Thereafter, the solution was filtered through a micro filtermade of polyethylene having a pore diameter of 0.10 μm and then througha micro filter made of polyethylene having a pore diameter of 0.05 μm toprepare a solution for coating-type underlayer coating for lithography.

Comparative Example 1

In 10 g of a solution containing 2 g of the polymer compound obtained inSynthesis Example 4 in propylene glycol monomethyl ether, 0.5 g oftetramethoxymethyl glycol uril and 0.02 g of p-toluene sulfonic acidwere mixed, and dissolved in 37.3 g of propylene glycol monomethyl etherand 19.4 g of propylene glycol monomethyl ether acetate to obtain asolution. Thereafter, the solution was filtered through a micro filtermade of polyethylene having a pore diameter of 0.10 μm and then througha micro filter made of polyethylene having a pore diameter of 0.05 μm toprepare a solution for anti-reflective coating.

Comparative Example 2

In 10 g of a solution containing 2 g of the polymer compound obtained inSynthesis Example 5 in tetrahydrofuran, 0.5 g of hexamethylol melamineand 0.05 g of p-toluene sulfonic acid were mixed, and dissolved in 39.5g of propylene glycol monomethyl ether to obtain a solution. Thereafter,the solution was filtered through a micro filter made of polyethylenehaving a pore diameter of 0.10 μm and then through a micro filter madeof polyethylene having a pore diameter of 0.05 μm to prepare a solutionfor anti-reflective coating.

Measurement of Optical Parameter

The solutions for coating-type underlayer coating prepared in Examples 1to 4 or the solutions for anti-reflective coating prepared inComparative Examples 1 and 2 were coated on silicon wafers by means of aspinner. The coated silicon wafers were baked at 205° C. for 1 minute ona hot plate to form coating-type underlayer coatings or anti-reflectivecoatings (film thickness 0.06 μm). On the coating-type underlayercoatings or antireflective coatings, refractive index (n) andattenuation coefficient (k) at a wavelength of 248 nm or 193 nm weremeasured with a spectroscopic ellipsometer. The results are shown inTable 1.

Dissolution Test in Photoresist Solvent

The solutions for coating-type underlayer coating prepared in Examples 1to 4 or the solutions for anti-reflective coating prepared inComparative Examples 1 and 2 were coated on silicon wafers by means of aspinner. The coated silicon wafers were baked at 205° C. for 1 minute ona hot plate to form coating-type underlayer coatings or anti-reflectivecoatings (film thickness 0.10 μm). The coating-type underlayer coatingsor anti-reflective coatings were dipped in a solvent used forphotoresists, for example ethyl lactate, and propylene glycol monomethylether and as a result it was confirmed that the resulting coating-typeunderlayer coatings or anti-reflective coatings were insoluble in thesesolvents.

Test of Intermixing with Photoresist

The solutions for coating-type underlayer coating prepared in Examples 1to 4 or the solutions for anti-reflective coating prepared inComparative Examples 1 and 2 were coated on silicon wafers by means of aspinner. The coated silicon wafers were baked at 205° C. for 1 minute ona hot plate to form coating-type underlayer coatings or antireflectivecoatings (film thickness 0.10 μm). On each of the coating-typeunderlayer coatings or anti-reflective coatings was coated acommercially available photoresist solution (trade name: UV113manufactured by Shipley Corporation) by means of a spinner. The coatedwafers were heated at 120° C. for 1 minute on a hot plate. Afterexposure of the photoresists to light, post exposure bake was performedat 115° C. for 1 minute. After developing the photoresists, the filmthickness of the coating-type underlayer coatings or anti-reflectivecoatings was measured and it was confirmed that no intermixing occurredbetween the coating-type underlayer coatings obtained from the solutionsfor coating-type underlayer coating prepared in Examples 1 to 4 or theanti-reflective coatings obtained from the solutions for anti-reflectivecoating prepared in Comparative Examples 1 and 2 and the photoresistlayers.

Measurement of Dry Etching Rate

The solutions for coating-type underlayer coating prepared in Examples 1to 4 or the solutions for anti-reflective coating prepared inComparative Examples 1 and 2 were coated on a silicon wafer by means ofa spinner. The coated silicon wafers were baked at 205° C. for 1 minuteon a hot plate to form coating-type underlayer coatings oranti-reflective coatings (film thickness 0.10 μm). Then, dry etchingrate on these underlayer coatings or anti-reflective coatings wasmeasured with RIE system ES401 manufactured by Nippon Scientific Co.,Ltd., RIE-10NR manufactured by SAMCO Inc., or TCP9400 manufactured byLam Research Co., Ltd.

In addition, similarly to the above, a coating was formed on a siliconwafer with a photoresist solution (trade name: UV113 manufactured byShipley Corporation) by means of a spinner. Then, dry etching rate wasmeasured with RIE system ES401 manufactured by Nippon Scientific Co.,Ltd., and compared with the dry etching rate of the coating-typeunderlayer coatings or anti-reflective coatings of Examples 1 to 4 orComparative Examples 1 and 2. The results are shown in Table 1.

Further, dry etching rate of the semiconductor substrate was measuredwith RIE-10NR manufactured by SAMCO Inc., or TCP9400 manufactured by LamResearch Co., Ltd., and compared with the dry etching rate of thecoating-type underlayer coatings or anti-reflective coatings of Examples1 to 4 or Comparative Examples 1 and 2. The results are shown in Table2.

In Table 2, Measurement (1) of dry etching rate ratio of thecoating-type underlayer coating of the present invention to the resist(coating-type underlayer coating/resist) was performed by using CF₄ gasas dry etching gas.

Measurement (2) of dry etching rate ratio of SiO₂ coating on thesubstrate to the coating-type underlayer coating of the presentinvention (SiO₂/coating-type underlayer coating) was performed by usingC₄F₈ gas as dry etching gas.

Measurement (3) of dry etching rate ratio of silicon nitride coating onthe substrate to the coating-type underlayer coating of the presentinvention (silicon nitride/coating-type underlayer coating) wasperformed by using CHF₃ gas as dry etching gas.

Measurement (4) of dry etching rate ratio of polysilicon coating on thesubstrate to the coating-type underlayer coating of the presentinvention (polysilicon/coating-type underlayer coating) was performed byusing Cl₂ gas as dry etching gas.

TABLE 1 Refractive Index (n) and Optical Absorption Coefficient (k)Refractive Index (n) Optical Absorption Coefficient (k) (wavelength 248nm) (wavelength 248 nm) Example 1 1.80 070 Example 2 1.62 0.87 Example 31.60 0.64 Example 4 1.48 0.68 Comparative 1.47 0.47 Example 1Comparative Example 2 Refractive Index (n) Optical AbsorptionCoefficient (k) (wavelength 193 nm) (wavelength 193 nm) Example 1 1.490.41 Example 2 1.54 0.32 Example 3 1.60 0.28 Example 4 1.61 0.21Comparative Example 1 Comparative 1.82 0.34 Example 2

TABLE 2 Dry Etching Rate Ratio (1) (2) (3) (4) Example 1 0.9 6.2 5.1 3.7Example 2 0.9 6.2 5.0 3.7 Example 3 1.0 7.0 4.5 3.1 Example 4 1.1 5.03.9 2.5 Comparative Example 1 1.3 3.7 2.8 2.0 Comparative Example 2 1.43.4 2.5 1.8

It is found from these results that the coating-type underlayer coatingmaterial for lithography of the present invention can provide anexcellent coating-type underlayer coating having a selection ratio ofdry etching rate close to that of photoresists, or a lower selectionratio of dry etching rate than that of photoresists, or a lowerselection ratio of dry etching rate than that of semiconductorsubstrates which is different from conventional high etch rateanti-reflective coatings, and further having an effect as ananti-reflective coating,

INDUSTRIAL APPLICABILITY

The purpose of the present invention is provide a coating-typeunderlayer coating for lithography having a selection ratio of dryetching rate close to that of photoresists, a coating-type underlayercoating for lithography having a lower selection ratio of dry etchingrate than that of photoresists, or a coating-type underlayer coating forlithography having a lower selection ratio of dry etching rate than thatof semiconductor substrates, that causes no intermixing with photoresistlayers and provides excellent photoresist pattern. In addition, thecoating-type underlayer coating material of the present invention canconfer a property for absorbing effectively reflection light fromsubstrates in a case where irradiation light having a wavelength of 248nm, 193 nm, 157 nm or the like is used in the micro-processing.

The coating-type underlayer coating forming composition of the presentinvention can form easily an underlayer coating through a coating systemfor example by coating the underlayer coating forming composition with aspinner, and heating. The composition of the present invention canapplied by use of these characteristics to a process in whichmulti-layer coating for the manufacture of semiconductor devices thatrequire micro-processing with small line width.

1. A coating-type underlayer coating forming composition for lithographycomprising a compound of formula (1):

wherein A is an organic group having an aromatic group, R₁ is hydroxygroup, an alkyl group, an alkoxy group, a halogen group, a thiol group,an amino group or an amide group, m1 is the number of A substituted onthe naphthalene ring and is an integer of 1 to 6, m2 is the number of R₁substituted on the naphthalene ring and is an integer of 0 to 5, a sumof m1 and m2 (m1+m2) is an integer of 1 to 6, in cases where the sum isan integer other than 6, the reminder is hydrogen atom, and n is thenumber of repeating units ranging from 2 to
 7000. 2. A coating-typeunderlayer coating forming composition for lithography comprising acompound of formula (2):

wherein A, R₁, m1, m2, and n are as defined in formula (1), Ar₁ is asubstituted or unsubstituted aromatic group.
 3. A coating-typeunderlayer coating forming composition for lithography comprising acompound of formula (3):

wherein X is a single bond, methylene group, C₂₋₁₀alkylene group, adivalent hydrocarbon group having C₂₋₁₀ether bond, or carbonyl group, Zis a linking group of —O— or —OC(═O)—, Ar₂ is an unsubstituted aromaticring or an aromatic ring substituted with carboxylic acid, a carboxylicacid ester group, hydroxy group, an alkyl group, an alkoxy group,sulfonic acid group, or a halogen group, and R₁, m1, m2 and n are asdefined in formula (1).
 4. A coating-type underlayer coating formingcomposition for lithography comprising a compound of formula (4):

wherein X and Z are as defined in formula (3), Ar₁ is as defined informula (2), Ar₂ is as defined in formula (3), and R₁, m1, m2, and n areas defined in formula (1).
 5. A coating-type underlayer coating formingcomposition for lithography comprising a compound of formula (5):

wherein X and Z are as defined in formula (3), Ar₂ is as defined informula (3), and R₁, m1, m2 and n are as defined in formula (1).
 6. Thecoating-type underlayer coating forming composition for lithographyaccording to claim 1, further comprising a crosslinking compound.
 7. Thecoating-type underlayer coating forming composition for lithographyaccording to claim 1, further comprising an acid, an acid generator, orboth of them.
 8. The coating-type underlayer coating forming compositionfor lithography according to claim 6, further comprising an acid, anacid generator, or both of them.
 9. A coating type underlayer coatingfor lithography obtained by coating the coating-type underlayer coatingforming composition according to claim 1 on a semiconductor substrateand baking it.
 10. A method for forming photoresist pattern for use inmanufacture of semiconductor device, comprising coating the coating-typeunderlayer coating forming composition according to claim 1 on asemiconductor substrate, and baking it to form a coating-type underlayercoating.
 11. A method for manufacturing semiconductor device comprisingthe steps of: forming a coating-type underlayer coating from thecoating-type underlayer coating forming composition according to claim1; forming a resist coating on the coating-type underlayer coating;forming a resist pattern by exposure to light and development; etchingthe coating-type underlayer coating by use of the resist pattern; andprocessing the semiconductor substrate by use of the patternedcoating-type underlayer coating.
 12. A method for manufacturingsemiconductor device comprising the steps of: forming a coating-typeunderlayer coating from the coating type underlayer coating formingcomposition according to claim 1; forming a hardmask on the coating-typeunderlayer coating; forming a resist coating further thereon; forming aresist pattern by exposure to light and development; etching thehardmask by use of the resist pattern; etching the coating-typeunderlayer coating by use of the patterned hardmask; and processing thesemiconductor substrate by use of the patterned coating-type underlayercoating.